Slow trees in a cli­mate of change

Los Angeles Times - - OP-ED - Jared Farmer is a pro­fes­sor of his­tory at Stony Brook Univer­sity and the au­thor of “Trees in Par­adise: A Cal­i­for­nia His­tory.” By Jared Farmer

In a time of re­lent­less change, it’s sooth­ing to con­tem­plate deeply rooted, long-lived trees. But now our cli­mate of un­cer­tainty af­fects even Great Basin bristle­cone pine, Pi­nus lon­gaeva, the species with the world’s old­est known in­di­vid­u­als. How should we re­spond? With alarm, in­dif­fer­ence or some­thing else?

Re­cently, a team of botanists pub­lished an ar­ti­cle on “di­ver­gent re­sponses of tree species and life stages to cli­matic warm­ing in Great Basin sub­alpine forests.” In the White Moun­tains of east­ern Cal­i­for­nia, tree lines are ascending. Bristle­cone pines have been less suc­cess­ful at col­o­niz­ing the new growth zone than neigh­bor­ing lim­ber pines. The sci­en­tists de­scribed lim­bers “leapfrog­ging” bristle­cones “in slow mo­tion.” Over time, P. lon­gaeva could face “over­all range con­trac­tion and pos­si­bly lo­cal ex­tir­pa­tions.”

What once might have been slow news, or no news, en­tered the fast news cy­cle. UC Davis, the lead au­thor’s em­ployer, pre­pared a press kit. Me­dia re­la­tions changed the metaphor from “leap frog in slow mo­tion” to “race to the top,” and im­plied that land man­agers should try to fix the game so that bristle­cone wins. Af­ter a jour­nal­ist adapted the univer­sity press re­lease, the AP is­sued it for syn­di­ca­tion with a sen­sa­tional head­line, and a tech­ni­cal study com­pleted its con­ver­sion into click­bait: “Sci­en­tists: Fu­ture of Old­est Tree Species on Earth in Peril.”

In truth, sci­en­tists are not wor­ried about the ex­tinc­tion of bristle­cone pine in the man­age­able fu­ture.

Ecol­o­gists can make ed­u­cated guesses about how bristle­cone pop­u­la­tions — which oc­cur with and with­out lim­ber pine — might change in the long term, mean­ing mil­len­ni­ums. That is dif­fer­ent than sooth­say­ing. In a sep­a­rate re­port, tree-ring re­searchers demon­strated that sub­alpine bristle­cones have grown faster in the last half cen­tury than any 50-year pe­riod in the last 3,700 years. Whether global warm­ing is “good” or “bad” for P. lon­gaeva de­pends on the time frame. Re­gard­less, it should give us pause that even the old­est trees on the high­est tree lines are sub­ject to our out-of-con­trol plan­e­tary ex­per­i­ment.

Let’s as­sume that over the next 1,000 or 10,000 years of hu­man-ac­cel­er­ated cli­mate change, lim­ber pine proves to be more adapt­able than bristle­cone pine. Would that be rea­son for anx­i­ety or sor­row? Why not praise the re­silience of Pi­nus flex­ilis, a tree that oc­curs from Canada to Mex­ico, in high and low al­ti­tudes, at­tain­ing ages up to 2,000 years.

The snag is that lim­bers lack mys­tique. Only one tree species can hold the ti­tle World’s Old­est, and bristle­cone pine has been that cham­pion since the 1950s.

A de­throned “old­est” ti­tle holder, giant se­quoia, re­mains iconic be­cause of its mon­u­men­tal size. Dur­ing the his­toric 2011 — 2017 drought, jour­nal­ists went to the Sierra Ne­vada again and again to ask field ex­perts if the big trees were im­per­iled. In fact, se­quoias held up re­mark­ably well. Re­porters duly sub­mit­ted sto­ries about how the gi­ants might suc­cumb, only be­lat­edly giv­ing at­ten­tion to the tens of mil­lions of dead and dy­ing trees of other species all around them.

Beyond com­mer­cial fac­tors — the al­go­rithms that de­cide which sto­ries are “en­gag­ing” — I won­der why some peo­ple “like” nar­ra­tives of an­cient trees in im­mi­nent dan­ger. Per­haps cli­mate ac­tivists be­lieve, with­out ev­i­dence, that alarmist sto­ries will win over skep­tics, con­trar­i­ans and de­niers. Or per­haps th­ese sto­ries are ex­pres­sions of col­lec­tive grief. Peo­ple who have lost en­vi­ron­men­tal hope may de­rive eco-schaden­freude from vi­su­al­iz­ing how cli­mate change fore­dooms even the most per­sis­tent or­gan­isms.

The car­bon cri­sis is chang­ing ev­ery­thing, though some things will change faster than oth­ers, and at the lo­cal level, global warm­ing will cre­ate win­ners along with losers. As a gen­eral propo­si­tion, to­day’s big old trees — win­ners in an older cli­mate— will even­tu­ally fall into the los­ing col­umn.

Con­sider the un­cer­tain fate of Cal­i­for­nia’s em­blem­atic megaf lora. Joshua trees could be pushed out of low-el­e­va­tion Joshua Tree Na­tional Park within a cen­tury. In Red­wood Na­tional and State Parks, the world’s tallest or­gan­isms rely on the marine layer and may be­come vul­ner­a­ble to sum­mer-fog de­cline. The in­di­vid­u­ally named gi­ants of Se­quoia Na­tional Park sur­vived the re­cent drought and worse ones in the past, yet it’s un­clear if they could with­stand an ex­treme year like 2014 once a decade, a po­ten­tial cli­mate sce­nario.

For those who love the Golden State’s su­perla­tive trees, this list of pos­si­bil­i­ties stirs dis­quiet. It’s un­der­stand­able to add a worry line for bristle­cones. At the same time, a dif­fer­ent moral can be taken from P. lon­gaeva, a species that spe­cial­izes in mak­ing do.

In the in­hos­pitable White Moun­tains, vis­i­tors linger amid un­hu­man but re­lat­able be­ings — trees that have stayed rooted in their home place for more than 4,000 years. The fed­er­ally pro­tected An­cient Bristle­cone Pine For­est en­cour­ages long-term imag­i­na­tion, a pre­cious re­source in our po­lit­i­cal econ­omy of short-ter­mism. We can use this deeper time frame to fret about trees in fu­ture mil­len­ni­ums. We might also take in­spi­ra­tion from th­ese Methuse­lahs to think ahead just one cen­tury, when the great­est cli­mate vic­tims will be hu­man be­ings. “Cli­mate Change in the Amer­i­can Mind,” a 2017 polling re­port, showed that Amer­i­cans are more con­cerned about the cli­matic threat to plants than peo­ple. Speak­ing as a plant per­son, I think that’s up­side-down. If we could swiftly tend to our world, in­clud­ing the weak and the poor, bristle­cones, at least, would slowly con­tinue to take care of them­selves.

Scott Smith As­so­ci­ated Press

WHETHER global warm­ing is good or bad for Cal­i­for­nia’s an­cient bristle­cone pines de­pends on the time frame.

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